For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningUniform Tire Quality Grading
Quality grades can be found where applicable on the tire sidewall between tread
shoulder and maximum section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system developed by the United States
National Highway Traffic Safety Administration ...
Additional Maintenance and Care
Your vehicle is an important investment and caring for it properly may help to
avoid future costly repairs. To maintain vehicle performance, additional maintenance
services may be required. It is recommended that your dealer perform these services
— their trained dealer technicians know your v ...
Exit Lighting
The headlamps, taillamps, parking lamps, back-up lamps, and license plate lamps
come on at night, or in areas with limited lighting, when the key is removed from
the ignition.
The dome lamps also come on when the key is removed from the ignition. The exterior
lights and dome lamps remain on a ...